Our overall objective is to understand the mechanism of active transport in molecular terms. We shall continue to study shock- releasable binding proteins of E. coli and how they are coupled to other proteins in the energy step of active transport. Carrier proteins will be purified from membrane vesicles. We have purified three membrane- bound dehydrogenases and we plan to investigate their localization and mechanism of action in membranes. We shall isolate more mutants, both those involving binding proteins and others where energy coupling is involved. We shall undertake to reassociate carrier proteins and dehydrogenases with membrane vesicles and other systems. We shall continue our investigation of the membrane Mg ions-ATPase of E. coli. We want to determine accurately the ratio of subunits, and the role of each subunit. It is expected that specific antisera will be helpful for this purpose. We also want to study the conditions and the protein factors necessary for reconstitution of oxidative phosphorylation involving deficient membranes and the purified Mg ions- ATPase. We are studying enzyme localization in Kaback vesicles, which are useful model systems for transport. We observe enzyme dislocation in such vesicles and wish to find a modified procedure for isolating then transporting vesicles without enzyme dislocation. Active transport in Ehrlich ascites cells is also under study.